I am attempting to calculate the vertical carrier mobility through a semiconductor powder sample coated on FTO using Spin Coating method. The I-V results I recorded using SMU 2401, shows current saturation at very low voltage like 0.3V, 0.4V etc. From Literature I found the saturation Value to be more than 2V. What could be the reason of showing this much low current saturation in my sample. I want know the possible reasons behind such result. whether the device is short? or any other reasons? I am attaching the images of (a) the configuration I chose for coating and I-V measurements (b) Corresponding I-V Graph of my sample (c) reference I-V plot taken from literature .